Microscope



R. G. GUTHRIE MIGROSGOPE Nov. 6, v1928. 1,690,677

Filed July 15, 1927 75 i '7 /0 y 4 D@ H I' Patented Nov. 6, 1928.

Micitoscorn.

Aprliatien filed @1y 15,

'Thi Kinvention relates lto improvements in '#37 '.-W' r "i :Mr-lf microscopes. More particularly l this inventionjelatesto improvements in means for 'nchargeableA focus "duri vii. provid@ delicate easily oplzablg 01' @Skivadve .adapted to bL a rse," adjustment Vand y lociri" f. m' f i ther" constructed with In order to obtain `accurate photoinicro-A graphs it has been attempted to re-focus the apparatus for each exposure, but this is not satisfactory as the plates are then not all scientifically correctly alike.

I have found that by providing an electromagnetic brake Vor lock it is possible to lock or brake the line adjustment on the microscope so as to maintain itabsolutely unchangeable for any given length of time. Accordingly my invention `is embodied in an attachment in the form of an electromagnetic brake or lock adapted to be easily and quickly att-ached to a microscope, camera or other apparatus. My invention is shown in connection with a microscope ofvstandard design and construction such as is used by scientists in micrometallographic Work, but obviously the use of the invention is not limited to this or any other particular apparatus. In the accompanying drawing. l n

Fig. 1 is a diagrammatic view of a micrometallographic apparatus' equipped with a locking device embodying the invention.

Fig. 2 is an enlarged front view of the apparatus with parts removed.

Fig. 3 is a plan view of the electromagnetic lock.

i Fig. 4 is a view thereof in elevation.

l Y metallographitz,Vv fincr-ofsoopsH are usuallyprovided ivithlineans( for1 positively" to obtain unchaiiigeable`J foetus; hevertheless*ioperablebykidbs22faiid 23. v

5 is a left hand view of Figure 4.

LEM, .IM-., A CORPQRA.-

iff Asshowa in Figure yi the uamifmaaii- 2",1 t 1"" :uw i V1; f i n. which receives `current from battery or the circuit. ""1 K Referring now( more particularly dtoFig- 'ure 2, thenumeralf13ldcniotes" the sta'nd'of a i "Standard microscope rhzetallog'Palchi-Q` piu-"i poss. ;"f1"4"is` the st-age'for, supportingithe yIfspecimen to'lbephotographed. 1G isthe i" f.' ing With a ipiniorif18 iii the usual nianneij a A fcoarser adgustment 19 having '.fap'lolck4 20;fa`nd 'their finely' ad] ustedby la 'inef adjustment y21 doma-,representeai@ i Shaft ai *fait t* ery 26 adapted to be engaged frictionally and i firmly by the correspondingly recessed head 27 on the core 28 of an electromagnet 29. The latter is movabl supported by a thin hanger 30 adapted to bre pivoted to the microscope as shown at 31 in Figure 2. The electromagnet 29 is suspended Within a protective casing 32 on a bracket 33. The terminal Wires 34, 34 are secured tobinding posts 35, 35 in the end of the casing.

The wires 34 are looped or flexed Within the casing to permit freelongitudinal movement of the electromagnet.

It will be seen, therefore, that the electromagnetic lockfconsists of two parts, namely an electromagnet adapted to act as a lock and y ment shaft 24 and the electromagnet unitis mounted in operative relation thereto by suitably aiixing the supporting bracket 33A and and then bythe iine adjustment, the opera-r torcloses t-hesivitchy 12 to close the circuit` through the. electromagnetj29 which then be-`A comes energized yand isv attractedbythe Wheel 26. lThe electromagnet Will instantly attach itselffto .the Wheel, the Ihead 27 litting the sameLsnugly. In fact, the Wheel Will itseltl ybecome part of the magnet as is obvious, and the Wheel Will remain immovable so long asl lthe Vcurrent c is on.y Consequently the ne adjustment willremaiirlocked during the operations.` When the current is turned oit,

the tine adjustment may again be operated byy turningthe knob323 and the electromagnet moves; away a slight distance from the wheel due to greater Weight ot the magnet acting Von the leftv hand side oft the pivot at 3l in an obvious manner. y i y While the invention is shown applied to amicroscope it is not limited thereto; yIt is usable for braking or locking a movableo r K' stationary? element Wit-hin the practical scope of its capacit-yt.. vIt'will also bef-understood that changes may be made Within the scope of the appended claims Without thereby departing from the principleo'f the invent-ion; 435

I claiin:-- e l. Ina microscope in combination a line adjustment mechanism tor focussing spurposes including a. shaft, a member secured to said sha't and comprising an operating knob 40 anda Wheel7 abracket secured to said micro-1` scope, an electromagnet mo'untecltor moverrment into operative relation Lto the SaidWhe'el,y -means on said magnet adapted to engage said j Wheeh'and means forfcnergizing saidl electro- 4455 magnet to cause yitl tobe attracted bythe wheel to lock` it yand the said` shaft againstr il" rotary movement.

2. In` amicrosrcope in `'combination a tine adjustmentl mechanism for focussing pur- 50 l poses including a shaft,A a-ivheel of magnetic"z material secured to said shaft, van electroymagnet, means tor pivotally suspending'the same :trom the microscope iii normallynon- 'engaged relation Withsaid wheeh'a head on k55l said electromagnet adapted rto `engage the` periphery ot' the Wheel, and meansffor ener-y gizingfsaidfelectromagnet to cause ittofbel y ,i attracted bythe Wheely to lock` itandfthe shaft againstI rotary movement. i

f ROBERT 

